Green Lantern Hal Jordan, investigating the disappearance of Evergreen City on Earth, discovers that Appa Ali Apsa, the lone remaining Guardian has been driven insane by loneliness. For companionship, Apsa has been uprooting cities from all the worlds he has visited and transporting them to the planet Oa, creating a patchwork known as the Mosaic World.
John Stewart, captured by Apsa, summons Jordan through their power rings and, together with Guy Gardner and the newly-returned Guardians, defeat Apsa.